FDA Approves 2 Vonoprazan Treatments for Helicobacter Pylori Infection

Today, the US Food and Drug Administration (FDA) issued approvals of 2 vonoprazan-based treatments for Helicobacter pylori (H. pylori) infection.

Marketed by Phathom Pharmaceuticals under the names Voquezna Triple Pak (vonoprazan, amoxicillin, clarithromycin) and Voquezna Dual Pak (vonoprazan, amoxicillin), the therapies were approved after positive safety and efficacy data from the phase 3 PHALCON-HP trial.

“The approval of VOQUEZNA treatment regimens offers physicians and patients 2 therapeutic options that showed superior eradication rates compared to proton pump inhibitor-based (PPI) lansoprazole triple therapy in the overall patient population in a pivotal trial,” said Terrie Curran, the president and CEO of Phathom.

The approval comes on the vonoprazan Prescription Drug User Fee Act (PDUFA) date. The FDA previously accepted 2 New Drug Applications (NDAs) for these vonoprazan dual and triple therapy treatments, giving them priority review designation.

H. pylori is a bacterial pathogen that may affect as many as 115 million people in the US alone. Phathom notes that eradication rates have dipped below 80% in the past few years. Left untreated, H. pylori can devolve into peptic ulcer disease and non-cardia gastric cancer.

“H. pylori eradication rates continue to decline in part due to antibiotic resistance, inadequate acid suppression, and complex treatment regimens, resulting in treatment failures and complications for patients,” Curran explained. “New therapies that have the potential to address the limitations of current treatments are needed and we look forward to bringing these innovative vonoprazan-based treatment options to the millions of H. pylori sufferers in the U.S.”

Treatment with an acid suppressant is the standard care for H. pylori. Thus, the necessity of vonoprazan, an oral small molecule potassium-competitive acid blocker (PCAB). PCABs block acid secretion in the stomach, and vonoprazan has demonstrated an ability to achieve pH levels that increase the efficacy of antibiotics. In both the approved treatments, vonoprazan is co-packaged with antibiotics.

With 1046 patients, Phathom reports that their phase 3 PHALCON-HP trial was the largest H pylori trial ever conducted in the US. Both vonoprazan dual and triple therapy regimens were non-inferior to lansoprazole triple therapy, in patients without an H. pylori strain resistant to clarithromycin or amoxicillin.

The H. pylori eradicationrate was 84.7% for vonoprazan triple therapy and 78.5% for the dual therapy, compared to the 78.8% eradication rate of lansoprazole. The 2 treatments were both superior to PPI-based triple therapy (lansoprazole with amoxicillin and clarithromycin) in all patients, including those with clarithromycin resistant strains of H. pylori.

The adverse events of the vonoprazan-based treatments were similar to those of lansoprazole triple therapy. The most common adverse events, affecting more than 2% of the study population, were diarrhea, dysgeusia, vulvovaginal candidiasis, abdominal pain, headache, hypertension, and nasopharyngitis.

Phathom Pharmaceuticals is a clinical late-stage biopharmaceutical company, primarily specializing in developing and marketing novel treatments for gastrointestinal diseases. Phathom anticipates the US commercial launch of vonoprazan dual and triple action in the third quarter of 2022.